This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Spatial distortions in EPI sequences and clipping of vascular signals during bolus passage peak a scanning sequence for perfusion with multiple echoes and temporal enhancement (PERMEATE) was developed, in which the confounding artifacts should be reduced. Data acquired with first (short) echo should be used to properly recover the vascular signals, whereas the later echoes are used to determine signals in the tissue manifesting better signal-to-noise ratio therein. Such state-of- the-art perfusion acquisition is complemented by a PWI post-processing pipeline, including correction for partialvolume effect (PVE) in vascular signals and susceptibility effect of the paramagnetic tracer in large vessels. To read about other projects ongoing at the Lucas Center, please visit http://rsl.stanford.edu/ (Lucas Annual Report and ISMRM 2011 Abstracts)